Riverside County public health officials are urging residents -- desert dwellers in particular -- to take precautions in the wake of four deaths that have been linked to July's extreme and sustained triple-digit temperatures.

In a news release issued Thursday by Riverside University Health System-Public Health, Dr. Cameron Kaiser, a county public health officer, said that extreme temps are expected to resume next week and that since July 7 the heat has "played a role" in the deaths of three Hemet residents and a Bermuda Dunes man.

The news release did not name those who have died, but it did describe them:

A 37-year-old man found dead July 7 in a Hemet parking lot.

A man and woman, ages 87 and 86, were found dead in a Hemet apartment.

And on Monday, in Bermuda Dunes, a 91-year-old man was found dead in a residence.

Officials stopped short of saying the deaths were caused by the heat, rather the "underlying health issues" of at least three of the four "made them more susceptible to the heat," according to the release.

“The elderly and the very young are particularly vulnerable to heat, and those with medical issues even more so,” Kaiser said. “If they’re in your family or they’re your neighbors, check in on them and make sure they’re doing okay. Even short periods of time in high temperatures can kill.”

Kaiser added that people who will be driving long distances should make sure their vehicles are running properly and that they carry extra water. Drivers should never leave leave children, senior citizens or pets in a parked vehicle, even for a short time.

Too much time in the heat can lead to heat-related illnesses such as heatstroke.

Symptoms of heatstroke, include:

Headache.

Dizziness.

Weakness or muscle pain.

And, nausea or vomiting.

There are 50 cooling centers throughout the county. The centers, coordinated by the Community Action Partnership of Riverside County, provide water, snacks and activities.